240 volts

If the order of the addition makes a difference in the results, then it is
a violation of the associative law of addition, so the addition isn't
being done properly. This is due to insufficient precision being used.
It is then an engineering decision whether higher precision must be used
or if the effect can be ignored (introduced error falls well within the
range of measurement or calculation errors or whatever) For example if
you were calculating power consumption of multi kW heaters and tried to
include the effect of the lady switching on a nightlight and its MV droop
effect.

On Sun, 2 Mar 2008 19:22:41 +0000 (UTC) Michael Moroney
| snipped-for-privacy@ipal.net writes:
|
|>On Sun, 2 Mar 2008 04:21:29 +0000 (UTC) Michael Moroney|>| |>| I know. My point was that if the order of addition affected the answer |>| enough to affect the outcome (at the needed precision), you simply need |>| more bits of precision in the variables. Like going from 24 bit "float"|>| to "double". Otherwise there will be some combination of inputs that will|>| bite you hard with the wrong answer.
|
|>Given that you have a finite precision to work with, sorting the values from|>smallest to largest is the most practical way. If infinite precision does|>happen to be available, then you can use that.
|
| If the order of the addition makes a difference in the results, then it is
| a violation of the associative law of addition, so the addition isn't
| being done properly. This is due to insufficient precision being used.
| It is then an engineering decision whether higher precision must be used
| or if the effect can be ignored (introduced error falls well within the
| range of measurement or calculation errors or whatever) For example if
| you were calculating power consumption of multi kW heaters and tried to
| include the effect of the lady switching on a nightlight and its MV droop
| effect.
Adding a small number to a large number requires more precision than either
alone needs to be expressed. What the order of addition does is allow that
dynamic to work in your favor. Sure, it is right to have enough precision
to do the addition. But you do have that enough precision in a dynamic
way when the addition is done from smallest to largest, without having to
expend the effort on more precise addition properties to achieve it.

Once again, you'll get inaccurate results because both the error margin in
the large number exceeds the value of any of the small numbers, and the
order of operations affects the outcome. Also, adding the small numbers
first isn't necessarily the best step. Consider when you have to sum an
array of numbers where two are nearly equal in magnitude, which is large,
but opposite in sign. The rest are small, smaller than the error in
either large number. If you add the small numbers first then add in one
of the large magnitude numbers, you'll lose many digits of precision.
Add in the other large number and you have a sum of similar magitude to
the small numbers but with substantial loss of precision. On the other
hand, if you add the large numbers first, you'll have a smallish sum where
adding the other small numbers makes sense.
Once again, if you are faced with such a situation, you'll have to either:
1) use higher precision variables (double vs. float for example);
2) decide that the smaller numbers fall within the margin of error and
should be disregarded; or
3) Find a better way.
By 3) I'll use this as an example: You have an empty dump truck and you
know its weight, and you need to know the gross weight of a full truck.
The truck scale used to weigh the truck can measure to what? 100 pounds?
10 pounds? You can measure the mass of each grain of sand to the
nearest billionth of a gram. Do you:
1) Weigh each grain of sand, add the weights and finally add the weight of
the truck?
2) Ignore the weight of the sand (after all, the weight of each grain is
much smaller than the error in the weight of the truck)?
3) Do something else, say weigh each scoop of sand as a front end
loader loads the truck, or just weigh the full truck?
You are arguing that 1) is the best solution. I claim it's absurd, and I
suspect most will agree. 2) isn't correct either, as a trip across a
bridge with a weight restriction will show. In this case "something else"
is the best choice.
The correct choice is an engineering situation that depends on the
situation.

On Mon, 3 Mar 2008 17:29:26 +0000 (UTC) Michael Moroney
| Once again, you'll get inaccurate results because both the error margin in
| the large number exceeds the value of any of the small numbers, and the
You don't know what the error margin is in this area of discussion because
it has not been specified. It might be high or it might be low. But either
of the correct ways to add numbers (with enough precision to handle the full
dynamic range from the smallest to largest ... or by sorting the numbers to
accumulate the sum smallest first to largest last) does not in and of itself
introduce any new error. It may well be far more precise than is necessary
for a given data set that has error in it. But in cases where the smaller
numbers exceed the absolute error of the larger numbers, the smaller numbers
are all noise no matter what you do.
| order of operations affects the outcome. Also, adding the small numbers
| first isn't necessarily the best step. Consider when you have to sum an
| array of numbers where two are nearly equal in magnitude, which is large,
| but opposite in sign. The rest are small, smaller than the error in
| either large number. If you add the small numbers first then add in one
| of the large magnitude numbers, you'll lose many digits of precision.
Of course you will, if the precision of the add is less than the full scale
of large and small number together. It is presumed you use addition with
enough precision for your needs in the sum. If the sum of all small numbers
is still so small it gets lost when the next number is very large, then so
be it. What the sorted summation method does is give those small numbers
that may have been lost BY THEMSELVES the opportunity to have the sum of
the small numbers make it into the level of precision the addition is using.
| Add in the other large number and you have a sum of similar magitude to
| the small numbers but with substantial loss of precision. On the other
| hand, if you add the large numbers first, you'll have a smallish sum where
| adding the other small numbers makes sense.
If you have two large numbers, one positive and one negative, and your level
of precision is such that the small numbers would not add in to either of
these large numbers, then you would not have these large numbers represented
with enough precision to get a sum that had a significance on the scale of
the smaller numbers.
This could well argue that you do need mucho precision in the arithmetic.
But if the end result only needs a certain level of precision, then all
those small numbers are unimportant and these two large numbers add up to
zero and that is the correct result in that case.
| Once again, if you are faced with such a situation, you'll have to either:
| 1) use higher precision variables (double vs. float for example);
| 2) decide that the smaller numbers fall within the margin of error and
| should be disregarded; or
| 3) Find a better way.
Again, adding sorted numbers works. There certainly are cases where the sum
of all the small numbers does not make it into the final sum. But that is
not a case of incorrect calculation; it is just a case where they were all
too insignificant to affect the final sum. This all presumes the precision
of the additions is enough for the final result. If that is not the case,
all hope is lost.
| By 3) I'll use this as an example: You have an empty dump truck and you
| know its weight, and you need to know the gross weight of a full truck.
| The truck scale used to weigh the truck can measure to what? 100 pounds?
| 10 pounds? You can measure the mass of each grain of sand to the
| nearest billionth of a gram. Do you:
|
| 1) Weigh each grain of sand, add the weights and finally add the weight of
| the truck?
| 2) Ignore the weight of the sand (after all, the weight of each grain is
| much smaller than the error in the weight of the truck)?
| 3) Do something else, say weigh each scoop of sand as a front end
| loader loads the truck, or just weigh the full truck?
|
| You are arguing that 1) is the best solution. I claim it's absurd, and I
| suspect most will agree. 2) isn't correct either, as a trip across a
| bridge with a weight restriction will show. In this case "something else"
| is the best choice.
Don't mix up the methods of measurement with the methods of arithmetic. Your
example involves measurement process. That is an entirely different thing.
| The correct choice is an engineering situation that depends on the
| situation.
Are you saying this about measurement? Or about calculation?

On Fri, 29 Feb 2008 05:13:04 +0000 (UTC) Michael Moroney
| snipped-for-privacy@ipal.net writes:
|
|>It depends on the context. If I am doing a calculation that _should_|>come up with the same value as 120 volts times the square root of three,|>but want to just express the result value to let someone else match it,|>I will use more digits. Usually 6 is enough to not just identify the|>system, but identify that the calculation did more than just get into|>the right ball park.
|
| But then the lady a mile up the road flips on a nightlight, causing the MV
| voltage to sag a tiny bit, and your 120.00000000 volts is no longer that,
| so the zillion digit precision calculation of the line-line voltage
| is no longer accurate...
If I had a meter that could measure RMS voltage to an accuracy and precision
of 1/100000000 volt, I'm more likely to curse the noise on the power line.
I don't use more precision on _measured_ values than the meansurement allows
for. It's when dealing with _definitions_ of values that more precision
will be used. The definition has as much accuracy as you want. It is the
expression of it that has precision.
|>| daestrom|>| I told you I was going to be pendantic .... :-)
|
|>Back when I was in junior high school, without the aid of any calculator|>or computer, I pondered the meaning of the frequency 3.58 MHz as it related|>to the TV broadcast standards (which at the time I "knew" to be 15,750 Hz|>horizontal and 60 Hz vertical. But I found a book in the school library|>that gave the value as 3.579545 MHz. Just that much information allowed|>me to "reverse engineer" this number to determine it came from 5 MHz times|>63 divided by 88, and really had "454545" repeated (3579545.45[45..] Hz),|>and that the horizontal frequency was really 15734.265734[265734..] Hz,|>and that the vertical frequency was really 59.940059[940059..] Hz. All
|
| As I understood it, the 3.579545 figure was deliberately chosen so to NOT
| be a multiple of either the V or H frequency, or the audio offset frequency
| so that the color signal would not interfere with/be interfered with any
| of the other signals, and 3.579545 was THE definition. Certainly there
| were tons of dirt-cheap crystals of that frequency (and 14.31818 MHz),
| no reason to divide down 5 MHz frequency. That number of digits made
| perfect sense in the definition since crystals could be cut to VERY
| precise frequencies (and in receivers were PLL'ed to the transmitter)
| Also, there was a common chip that divided the colorburst frequency down
| to 60 Hz (intended to use a common cheap crystal as a time base for digital
| clocks). In order to work correctly the colorburst xtal had to really be
| 3.579540 MHz. (it divided by 59659)
Yes, it is true the value was chosen to avoid integer relations to the
vertical and horizontal frequency. It was also chosen so that sidebands
of the horizontal modulated on the color would not hit the center of the
audio subcarrier at +4.5 MHz.
You can read the definition of the color subcarrier freqyency in the FCC
rules. If the frequency was chosen without that definition in mind, then
it is very amazing coincidence.
The _definition_ does not mean that the frequency has to actually be
derived from 5 MHz in implementations. The definition is a basis for
testing the implementation in some way, or calibrating it.
|>semantically, I need a much more precise value. Would you recognize it|>as the NTSC color subcarrier frequency if I called it 3.6 MHz? or 4 MHz?
|
| As the definition was to a very high standard that was also met in real
| life, 3.579545 MHz is the correct term, as a TV whose color frequency
| was running at 3.6 MHz or 4 MHz (or even 3.58 MHz) would not display
| colors correctly at all!
Such oscillators could be pulled in to sync at the arriving frequency.
But the further away their non-sync frequency is, the less stable they
will be. If your crystal is cut for 3.579545 and the broadcaster is
sending 3.579545454545454545 then the circuit will syncronize it.
|>Do you do any computer programming? If so, do you just add up a long|>list of floating point values in the order given, or do you sort them|>so you accumulate the sum by adding the lowest values first?
|
| I do computer programming and would add the numbers in the order given.
| If the required precision of the result exceeded that of the computer's
| "float" precision, I'd use "double" (or higher) and add in the order given.
If the scale of the numbers is large, and the count of numbers is also
large, the inaccuracy of such addition could become significant.

Bullshit. Adding more than an extra digit or two to the
specification gains you absolutely nothing, other a than a complete
waste of your time.

Sigh. The reasons are VERY well laid out in older TV design
handbooks. Maybe a little reading will open your eyes?

The 5 MHz reference was chosen, because it was generally available at
the transmitter site to verify the frequency.

Phil, quit being a complete and total asshole. No station has the
ability to measure that far, and the FCC rounds it to the nearest full
digit, plus or minus 10 Hz. Because of this, the frequency is measured
to the spec, plus one extra digit to minimize random changes. Believe
me, it takes long enough to zero the master crystal in a sync generator,
or frame store that once it is within one hertz of the spec, you stop.
it will drift up and down a few cycles, even in an oven.
Yes, you can play with your calculations all you want, but its just a
total waste of time, like almost everything else you post. Even IF the
color burst DID happen to drift to fall exactly on your ridiculous set
of numbers, the TV set still wouldn't be exactly on frequency, because
the seven cycles of color burst are used to pull the frequency close to,
but not exactly to 3.579545 MHz. I should know. I was responsible for
a 5 MW EIRP UHF TV transmitter, not a 'master control operator' who
signed the form and got that pretty little certificate that acknowledged
that the FCC knew I existed. Hell, we had a young hippy flower child who
pulled third shift as a master control operator at one time. She didn't
even know ohm's law, but she was excellent at filling out the log, and
watching for problems. She was on the phone to the engineers the second
something wasn't right, if one of the engineers wasn't on site.

On Sat, 01 Mar 2008 20:11:15 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> I don't use more precision on _measured_ values than the meansurement allows|> for. It's when dealing with _definitions_ of values that more precision|> will be used. The definition has as much accuracy as you want. It is the|> expression of it that has precision.
|
|
| Bullshit. Adding more than an extra digit or two to the
| specification gains you absolutely nothing, other a than a complete
| waste of your time.
When a measurement is inaccurate, a reduction in precision does little
more than encapsulate thet inaccuracy. The error is still the same.
When you multiply two values with a range of error, that range of error
increases to accomodate the extremes.
If you multiply a measured value (which has some error) by a defined
value with a reduced precision (that's error, too), that increases the
error.
But I take it you don't care.
BTW, the amount of _my_ time that increases to do the extra digits is
extremely small. I have much practice in doing it. Maybe you don't.
|> Yes, it is true the value was chosen to avoid integer relations to the|> vertical and horizontal frequency. It was also chosen so that sidebands|> of the horizontal modulated on the color would not hit the center of the|> audio subcarrier at +4.5 MHz.|> |> You can read the definition of the color subcarrier freqyency in the FCC|> rules. If the frequency was chosen without that definition in mind, then|> it is very amazing coincidence.
|
|
| Sigh. The reasons are VERY well laid out in older TV design
| handbooks. Maybe a little reading will open your eyes?
Are you talking about before or after color?
I've read the books. I wonder if you ever did.
|> The _definition_ does not mean that the frequency has to actually be|> derived from 5 MHz in implementations. The definition is a basis for|> testing the implementation in some way, or calibrating it.
|
|
| The 5 MHz reference was chosen, because it was generally available at
| the transmitter site to verify the frequency.
You certainly can derive the color subcarrier frequency from 5 MHz if you
want to (or from 15 MHz). But whether that readily available 5 MHz is
used to directly derive the color subcarrier frequency or is merely used
to calibrate an oscillator tuned to the color subcarrier frequency, my
point is still the same.
|> Such oscillators could be pulled in to sync at the arriving frequency.|> But the further away their non-sync frequency is, the less stable they|> will be. If your crystal is cut for 3.579545 and the broadcaster is|> sending 3.579545454545454545 then the circuit will syncronize it.
|
|
| Phil, quit being a complete and total asshole. No station has the
| ability to measure that far, and the FCC rounds it to the nearest full
| digit, plus or minus 10 Hz. Because of this, the frequency is measured
| to the spec, plus one extra digit to minimize random changes. Believe
| me, it takes long enough to zero the master crystal in a sync generator,
| or frame store that once it is within one hertz of the spec, you stop.
| it will drift up and down a few cycles, even in an oven.
Why is it that people like you always have to make personal attacks instead
of just arguing the applicable points you disagree with?
I already said the FCC requires it be plus or minus 10 Hz.
| Yes, you can play with your calculations all you want, but its just a
| total waste of time, like almost everything else you post. Even IF the
| color burst DID happen to drift to fall exactly on your ridiculous set
| of numbers, the TV set still wouldn't be exactly on frequency, because
| the seven cycles of color burst are used to pull the frequency close to,
| but not exactly to 3.579545 MHz. I should know. I was responsible for
| a 5 MW EIRP UHF TV transmitter, not a 'master control operator' who
| signed the form and got that pretty little certificate that acknowledged
| that the FCC knew I existed. Hell, we had a young hippy flower child who
| pulled third shift as a master control operator at one time. She didn't
| even know ohm's law, but she was excellent at filling out the log, and
| watching for problems. She was on the phone to the engineers the second
| something wasn't right, if one of the engineers wasn't on site.
If you think my posts are a waste of time, then I have a suggestion for
you ... don't read them anymore. Then you'll not feel any need to post
a followup and waste even more time.
I've never said that one subcarrier burst would be syncronize a local
oscillator to exactly the frequency the transmitter is using. But with
many bursts, as long as the local oscillator is not so far off as to be
a half-horizontal frequency displacement, it will _accumulate_ the same
exact number of cycles. That will center the spectral energy around
the transmitter's subcarrier frequency. The closer that local oscillator
is tuned to the correct frequency, the narrower the energy band will be.
That means a more stable oscillator and better color.
Neither being responsible for a transmitter, nor being a master control
operator, means you necessarily will understand how an oscilator under
syncronization will behave and produce a complex waveform. Maybe if you
read up more on radio theory ... where you could design a transmitter
instead of just flip them on and replace bad tubes ... then maybe you
would "get it".

Both. The library at Cincinnati Electronics had all the books from
the original Crosley engineering department, along with all of the IRE
and IEEE papers on Television, and covered every system that was
presented to the FCC, and ALL of the test results.

Sigh. No. of course not, you dumb ass. No one but you has ever read
them. They were written just so you could show off to everyone. That's
why i have a nice collection in my personal library. I always spend
lots of money on books I don't read.

5 and or 10 MHz have been the in house reference for decades. The
first frequency counters acceptable for TV use were built with ovenized
oscillators that produced at least one of these frequencies. The most
common counter was the HP 5245L with the proper front end plug in.

Why is it people like you, who have NEVER done the work talk down to
those who have?

You also said that it was +/- 10 Hz at 14.318180 MHz, when it is +/-
40 Hz

If someone doesn't call you on your bullshit and blunders, then the
people who have no clue will think that you are right.

You stated that it would be pulled to whatever the burst frequency
was.

You really have no clue, do you? In most burst circuits, more that
two cycles difference, and it will not be pulled to the subcarrier
frequency. Do you have a studio grade sync generator, a broadcast
quality waveform monitor, or a broadcast grade vectorscope?

That old ham radio smugness is showing, Phil. I built and rebuilt TV
transmitters, and one entire TV station from an empty building. The only
tubes in the last transmitter were EEV Klystrons that cost $45,000 each,
and produced 65 KW of RF. Have you ever worked with one of those? How
about repairing a video effects unit with a three phase 208 input, and a
1000A 5.00 VDC output power supply? All work had to be done hot. All
the signals had to be adjusted to under a half degree phase shift, or it
was visible, on air. Have you ever stood inside a TV transmitter, on
the plate supply wile it's on the air to make an emergency repair? have
you spent a half hour centering the range of the transmitter's LO so it
centers perfectly around the center frequency? How about
troubleshooting and repairing studio cameras between live shots? You
think highly of yourself, and you don't know shit.
Also, have you ever tried to match a set of 16 6146 tubes for a
distributed video amplifier for the video modulator stage on a 1950's
RCA TTU25B transmitter? It can take days, and a couple hundred tubes to
select a set from. You don't just stick a tube in a TV transmitter and
expect it to work properly. In fact, I wrote an improved service manual
for the gates transmitters we used at the AFRTS station I was assigned
to. I could generally get back on the air in under two minutes, then
fine tune everything. The biggest problem I had was a station manager
with a ham radio license who kept moistening the transmitter, and
compressing the sync. The idiot couldn't grasp the difference between
his Swan SSB rig and a broadband TV transmitter. You don't tune a TV
transmitter for peak power, it has to be aligned with test equipment to
have a flat video response.
Have you ever built a communications system for the ISS? Selectable
bandwidths to 40 Mbps, and it allowed audio, video and data transfer at
the same time? No. While you are busy playing with a calculator, SOME
of us were actually doing real work in the RF world.
A ham radio license and $20 can get you a crappy cup of coffee, and
little more.

On Sat, 01 Mar 2008 23:48:31 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> On Sat, 01 Mar 2008 20:11:15 -0500 Michael A. Terrell|> |>|> |> I don't use more precision on _measured_ values than the meansurement
allows
|> |> for. It's when dealing with _definitions_ of values that more precision|> |> will be used. The definition has as much accuracy as you want. It is the|> |> expression of it that has precision.|> ||> ||> | Bullshit. Adding more than an extra digit or two to the|> | specification gains you absolutely nothing, other a than a complete|> | waste of your time.|> |> When a measurement is inaccurate, a reduction in precision does little|> more than encapsulate thet inaccuracy. The error is still the same.|> |> When you multiply two values with a range of error, that range of error|> increases to accomodate the extremes.|> |> If you multiply a measured value (which has some error) by a defined|> value with a reduced precision (that's error, too), that increases the|> error.|> |> But I take it you don't care.|> |> BTW, the amount of _my_ time that increases to do the extra digits is|> extremely small. I have much practice in doing it. Maybe you don't.|> |> |> Yes, it is true the value was chosen to avoid integer relations to the|> |> vertical and horizontal frequency. It was also chosen so that sidebands|> |> of the horizontal modulated on the color would not hit the center of the|> |> audio subcarrier at +4.5 MHz.|> |>|> |> You can read the definition of the color subcarrier freqyency in the FCC|> |> rules. If the frequency was chosen without that definition in mind, then|> |> it is very amazing coincidence.|> ||> ||> | Sigh. The reasons are VERY well laid out in older TV design|> | handbooks. Maybe a little reading will open your eyes?|> |> Are you talking about before or after color?
|
|
| Both. The library at Cincinnati Electronics had all the books from
| the original Crosley engineering department, along with all of the IRE
| and IEEE papers on Television, and covered every system that was
| presented to the FCC, and ALL of the test results.
So there are books that talk about why the particular frequency was chosen
for the color subcarrier, before there was color?
|> I've read the books. I wonder if you ever did.
|
|
|
| Sigh. No. of course not, you dumb ass. No one but you has ever read
| them. They were written just so you could show off to everyone. That's
| why i have a nice collection in my personal library. I always spend
| lots of money on books I don't read.
At least you are being honest. I have only one book that deals with TV
technology. The rest I have read from the library.
|
|
|> ||> ||> | The 5 MHz reference was chosen, because it was generally available at|> | the transmitter site to verify the frequency.|> |> You certainly can derive the color subcarrier frequency from 5 MHz if you|> want to (or from 15 MHz). But whether that readily available 5 MHz is|> used to directly derive the color subcarrier frequency or is merely used|> to calibrate an oscillator tuned to the color subcarrier frequency, my|> point is still the same.
|
|
| 5 and or 10 MHz have been the in house reference for decades. The
| first frequency counters acceptable for TV use were built with ovenized
| oscillators that produced at least one of these frequencies. The most
| common counter was the HP 5245L with the proper front end plug in.
And?
|> |> Such oscillators could be pulled in to sync at the arriving frequency.|> |> But the further away their non-sync frequency is, the less stable they|> |> will be. If your crystal is cut for 3.579545 and the broadcaster is|> |> sending 3.579545454545454545 then the circuit will syncronize it.|> ||> ||> | Phil, quit being a complete and total asshole. No station has the|> | ability to measure that far, and the FCC rounds it to the nearest full|> | digit, plus or minus 10 Hz. Because of this, the frequency is measured|> | to the spec, plus one extra digit to minimize random changes. Believe|> | me, it takes long enough to zero the master crystal in a sync generator,|> | or frame store that once it is within one hertz of the spec, you stop.|> | it will drift up and down a few cycles, even in an oven.|> |> Why is it that people like you always have to make personal attacks instead|> of just arguing the applicable points you disagree with?
|
|
| Why is it people like you, who have NEVER done the work talk down to
| those who have?
What work? Have you _designed_ a complete TV encoding and transmission
system from the ground up? Can you even do the Fourier transforms (among
other things), needed to understand the signals and spectrum energy needed
to make the design effective?
|> I already said the FCC requires it be plus or minus 10 Hz.
|
|
| You also said that it was +/- 10 Hz at 14.318180 MHz, when it is +/-
| 40 Hz
The FCC requirement of +/- 10 Hz is for the on-air subcarrier. Do the
math to figure out what it needs to be for other frequencies you might
derive the subcarrier from.
|> If you think my posts are a waste of time, then I have a suggestion for|> you ... don't read them anymore. Then you'll not feel any need to post|> a followup and waste even more time.
|
|
| If someone doesn't call you on your bullshit and blunders, then the
| people who have no clue will think that you are right.
If you think I do that, then be specific and to the point. There is no
need to make personal attacks. You have done that a lot, as have a small
handful of others on Usenet. One of them even posts here a lot.
|> I've never said that one subcarrier burst would be syncronize a local|> oscillator to exactly the frequency the transmitter is using.
|
|
| You stated that it would be pulled to whatever the burst frequency
| was.
But I did not say that one burst alone would do that. You implied that
I did and that was wrong on your part.
|> But with|> many bursts, as long as the local oscillator is not so far off as to be|> a half-horizontal frequency displacement, it will _accumulate_ the same|> exact number of cycles. That will center the spectral energy around|> the transmitter's subcarrier frequency. The closer that local oscillator|> is tuned to the correct frequency, the narrower the energy band will be.|> That means a more stable oscillator and better color.
|
|
| You really have no clue, do you? In most burst circuits, more that
| two cycles difference, and it will not be pulled to the subcarrier
| frequency. Do you have a studio grade sync generator, a broadcast
| quality waveform monitor, or a broadcast grade vectorscope?
You seem to be the one with no clue.
Two cycles difference of what? Or do you mean 2 Hz? Well, I have news
for you ... an oscillator that would naturally oscillate at 2 Hz from
the transmitted signal can be pulled to that signal. Sure, it will
slip between burst pulses. But at 2 Hz difference, it's not that much.
It would be about 0.04576 degrees of phase by the time the next burst
comes along. You wouldn't even notice the color shift from left to
right.
|> Neither being responsible for a transmitter, nor being a master control|> operator, means you necessarily will understand how an oscilator under|> syncronization will behave and produce a complex waveform. Maybe if you|> read up more on radio theory ... where you could design a transmitter|> instead of just flip them on and replace bad tubes ... then maybe you|> would "get it".
|
|
| That old ham radio smugness is showing, Phil. I built and rebuilt TV
| transmitters, and one entire TV station from an empty building. The only
| tubes in the last transmitter were EEV Klystrons that cost $45,000 each,
| and produced 65 KW of RF. Have you ever worked with one of those? How
| about repairing a video effects unit with a three phase 208 input, and a
| 1000A 5.00 VDC output power supply? All work had to be done hot. All
| the signals had to be adjusted to under a half degree phase shift, or it
| was visible, on air. Have you ever stood inside a TV transmitter, on
| the plate supply wile it's on the air to make an emergency repair? have
| you spent a half hour centering the range of the transmitter's LO so it
| centers perfectly around the center frequency? How about
| troubleshooting and repairing studio cameras between live shots? You
| think highly of yourself, and you don't know shit.
I did not ask if you built. By father has built lots of electronic stuff
and he has zero clue how any of it works. Just because your stuff costs
a lot more only shows you are probably a lot more careful following the
directions to the letter.
But can you _design_ an NTSC encoding system? I have.
| Also, have you ever tried to match a set of 16 6146 tubes for a
| distributed video amplifier for the video modulator stage on a 1950's
| RCA TTU25B transmitter? It can take days, and a couple hundred tubes to
| select a set from. You don't just stick a tube in a TV transmitter and
| expect it to work properly. In fact, I wrote an improved service manual
| for the gates transmitters we used at the AFRTS station I was assigned
| to. I could generally get back on the air in under two minutes, then
| fine tune everything. The biggest problem I had was a station manager
| with a ham radio license who kept moistening the transmitter, and
| compressing the sync. The idiot couldn't grasp the difference between
| his Swan SSB rig and a broadband TV transmitter. You don't tune a TV
| transmitter for peak power, it has to be aligned with test equipment to
| have a flat video response.
No I have not matched a set of 16 6146 tubes. This relates to understanding
the color subcarrier how?
| Have you ever built a communications system for the ISS? Selectable
| bandwidths to 40 Mbps, and it allowed audio, video and data transfer at
| the same time? No. While you are busy playing with a calculator, SOME
| of us were actually doing real work in the RF world.
There's plenty of real work that involves not knowing anything about
waveforms, signals, or even mathematics. It obviously shows from some
of the errors you've made in posts that you think you are so great
because you've have your hands on all this stuff. But you couldn't
create a mathematical model for how it works.

Yes, ones printed during the development and the deployment of
color. They went into great detail about the problems expected, and the
changes needed to prevent them.

Once again, sarcasm goes right over your head.

And what? Either ask a question or shut up, troll.

Phil, some people are intuitive, and can see how things work. Others
need a pencil to take a crap.

I did. You are the one who claimed it was still +/- 10 Hz at
14.318180 MHz

Did you ever think that they are doing because you are wrong?

Sigh. :(

Right :(

So, you have never looked at what your design is capable of? That is
exactly what I expected

Ok. sure. yeah.
You have no clue, phil. The chroma would change from the left to the
right side of the screen if the burst oscillator isn't closer to the
expected frequency. You don't think so, but I've worked with several
video directors who could see that across the room. The burst is used
to fine tune the phasing, and the tint control is used to manually trim
it. It sets the center frequency, and if you were right, there would be
no way to set the tint.

What directions? A lot of components were obsolete, and very little
documentation had survived over the years. I had schematics, and parts
lists with RCA stock numbers, but RCA was out of the broadcast
business. It required thinking on your feet, and being able to redesign
some stages to work. Tell me where you would find a RF component that
hadn't been built in 20 years, and the old one was burnt beyond
recognition? What would you do if some dumb ass had brazed the custom
made brass fittings in the cooling circuit to the copper pipe, over some
bad solder. Without them, the transmitter was scrap.

Small potatoes. Have you designed an FQPSK encoding system, and the
decoding system? Hell, I've designed and built test fixtures that were
more complex. NTSC encoders were done with a handful of tubes and a
delay line for the sync. have you ever designed video amps with a 3 dB
point at 40 MHz, and less than .5 dB ripple over the entire pass band?
I suppose you'll be bragging abut designing buggy whips, too? The
large semiconductor manufacturers have obsoleted their NTSC chipsets,
because of HDTV. No one will be designing any new NTSC encoders. Have
you designed and built a low phase noise synthesizer to track deep space
probes? It operated in three adjacent segments to cover 370 MHz to 520
MHz continuous. All the math in the world wouldn't predict all the
quirks in a design like that. A lifetime of experience does. Simple
things, like changing from an uncased disk capacitor to a SMD part of
better quality caused the phase noise to shoot through the roof. All
the math in the world wouldn't explain it, but being VERY familiar with
RF PC board design made it obvious. Something that the other engineers
overlook, because they had no hands on experience with that design. The
large Vias that had been used to mount the uncased ceramics had to be
filled, all the way to prevent them from being low value inductors in
the ground plane.

Phil, you don't understand much of anything. If that distributed
amplifier isn't balanced, the chroma doesn't get to the modulator. The
burst was the highest frequency passed by the video amplifier, and
mismatched tubes cause a loss of response at the higher frequencies, and
some phase shift.

So, you would spend month reinventing hundreds of wheels, rather than
use what you already know? I went through the paper and pencil math
phase at around 13 years old, but I'VE outgrown it. A mathematical
model doesn't do any work. A piece of working equipment does. Your
models don't deal wth real world issues, only what would be in a perfect
universe. We designed and built $80,000 telemetry receivers without all
your excessive math, and they worked so well that we couldn't keep up
with the orders for a year or more. How many multi-million dollar
contracts do you get from your anal retentive math?

On Sun, 02 Mar 2008 13:47:07 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> |> | Sigh. The reasons are VERY well laid out in older TV design|> |> | handbooks. Maybe a little reading will open your eyes?|> |>|> |> Are you talking about before or after color?|> ||> ||> | Both. The library at Cincinnati Electronics had all the books from|> | the original Crosley engineering department, along with all of the IRE|> | and IEEE papers on Television, and covered every system that was|> | presented to the FCC, and ALL of the test results.|> |> So there are books that talk about why the particular frequency was chosen|> for the color subcarrier, before there was color?
|
|
| Yes, ones printed during the development and the deployment of
| color. They went into great detail about the problems expected, and the
| changes needed to prevent them.
|
|
|> |> I've read the books. I wonder if you ever did.|> ||> ||> ||> | Sigh. No. of course not, you dumb ass. No one but you has ever read|> | them. They were written just so you could show off to everyone. That's|> | why i have a nice collection in my personal library. I always spend|> | lots of money on books I don't read.|> |> At least you are being honest. I have only one book that deals with TV|> technology. The rest I have read from the library.
|
|
| Once again, sarcasm goes right over your head.
Who's sarcasm is the more subtle, eh?
|> | 5 and or 10 MHz have been the in house reference for decades. The|> | first frequency counters acceptable for TV use were built with ovenized|> | oscillators that produced at least one of these frequencies. The most|> | common counter was the HP 5245L with the proper front end plug in.|> |> And?
|
|
| And what? Either ask a question or shut up, troll.
How does what you said apply? Why don't you connect it to what was being
talked about?
|> | Why is it people like you, who have NEVER done the work talk down to|> | those who have?|> |> What work? Have you _designed_ a complete TV encoding and transmission|> system from the ground up? Can you even do the Fourier transforms (among|> other things), needed to understand the signals and spectrum energy needed|> to make the design effective?
|
|
| Phil, some people are intuitive, and can see how things work. Others
| need a pencil to take a crap.
You also need some paper with that pencil.
|> |> I already said the FCC requires it be plus or minus 10 Hz.|> ||> ||> | You also said that it was +/- 10 Hz at 14.318180 MHz, when it is +/-|> | 40 Hz|> |> The FCC requirement of +/- 10 Hz is for the on-air subcarrier. Do the|> math to figure out what it needs to be for other frequencies you might|> derive the subcarrier from.
|
|
| I did. You are the one who claimed it was still +/- 10 Hz at
| 14.318180 MHz
Fine, whatever you say.
|> If you think I do that, then be specific and to the point. There is no|> need to make personal attacks. You have done that a lot, as have a small|> handful of others on Usenet. One of them even posts here a lot.
|
|
| Did you ever think that they are doing because you are wrong?
Did you ever think that maybe you ought to just point out specifically
what you think is wrong, when someone posts something you think is wrong,
and include what you think is right? And do that post as a direct
followup to the specific post that has what you think was wrong.
|> | You really have no clue, do you? In most burst circuits, more that|> | two cycles difference, and it will not be pulled to the subcarrier|> | frequency. Do you have a studio grade sync generator, a broadcast|> | quality waveform monitor, or a broadcast grade vectorscope?|> |> You seem to be the one with no clue.
|
|
| So, you have never looked at what your design is capable of? That is
| exactly what I expected
Why would I have broadcast grade studio equipment at home?
|> Two cycles difference of what? Or do you mean 2 Hz? Well, I have news|> for you ... an oscillator that would naturally oscillate at 2 Hz from|> the transmitted signal can be pulled to that signal. Sure, it will|> slip between burst pulses. But at 2 Hz difference, it's not that much.|> It would be about 0.04576 degrees of phase by the time the next burst|> comes along. You wouldn't even notice the color shift from left to|> right.
|
|
| Ok. sure. yeah.
|
|
| You have no clue, phil. The chroma would change from the left to the
| right side of the screen if the burst oscillator isn't closer to the
| expected frequency. You don't think so, but I've worked with several
| video directors who could see that across the room. The burst is used
| to fine tune the phasing, and the tint control is used to manually trim
| it. It sets the center frequency, and if you were right, there would be
| no way to set the tint.
Yes it would change. I never said it would not. But I did the calculations
and the amount of change (0.04576 degrees of phase) is so small it would
most likely not even make a one bit difference if the resultant color was
digitized.
Maybe you are talking about an oscillator that is off way more than 2 Hz?
| What directions? A lot of components were obsolete, and very little
| documentation had survived over the years. I had schematics, and parts
| lists with RCA stock numbers, but RCA was out of the broadcast
| business. It required thinking on your feet, and being able to redesign
| some stages to work. Tell me where you would find a RF component that
| hadn't been built in 20 years, and the old one was burnt beyond
| recognition? What would you do if some dumb ass had brazed the custom
| made brass fittings in the cooling circuit to the copper pipe, over some
| bad solder. Without them, the transmitter was scrap.
And did you have to do math? Vector math? Trig? I wonder what part
you would have failed at if you had been called on to do it.
| Small potatoes. Have you designed an FQPSK encoding system, and the
| decoding system? Hell, I've designed and built test fixtures that were
| more complex. NTSC encoders were done with a handful of tubes and a
| delay line for the sync. have you ever designed video amps with a 3 dB
| point at 40 MHz, and less than .5 dB ripple over the entire pass band?
And yet you don't know how many degrees of phase change take place between
two sine waves only 2 Hz apart in frequency over the time a one video line?
| I suppose you'll be bragging abut designing buggy whips, too? The
| large semiconductor manufacturers have obsoleted their NTSC chipsets,
| because of HDTV. No one will be designing any new NTSC encoders. Have
| you designed and built a low phase noise synthesizer to track deep space
| probes? It operated in three adjacent segments to cover 370 MHz to 520
| MHz continuous. All the math in the world wouldn't predict all the
| quirks in a design like that. A lifetime of experience does. Simple
| things, like changing from an uncased disk capacitor to a SMD part of
| better quality caused the phase noise to shoot through the roof. All
| the math in the world wouldn't explain it, but being VERY familiar with
| RF PC board design made it obvious. Something that the other engineers
| overlook, because they had no hands on experience with that design. The
| large Vias that had been used to mount the uncased ceramics had to be
| filled, all the way to prevent them from being low value inductors in
| the ground plane.
Sure, experience helps. But getting math wrong can still destroy any
design project.
|> No I have not matched a set of 16 6146 tubes. This relates to understanding|> the color subcarrier how?
|
|
| Phil, you don't understand much of anything. If that distributed
| amplifier isn't balanced, the chroma doesn't get to the modulator. The
| burst was the highest frequency passed by the video amplifier, and
| mismatched tubes cause a loss of response at the higher frequencies, and
| some phase shift.
So if those 16 tubes are not perfectly matched, no signal gets out at
all? Maybe you need a whole different approach.
Why are you using 6146 tubes to pass chroma? Oh, wait, you didn't design
this.
|> There's plenty of real work that involves not knowing anything about|> waveforms, signals, or even mathematics. It obviously shows from some|> of the errors you've made in posts that you think you are so great|> because you've have your hands on all this stuff. But you couldn't|> create a mathematical model for how it works.
|
|
| So, you would spend month reinventing hundreds of wheels, rather than
| use what you already know? I went through the paper and pencil math
| phase at around 13 years old, but I'VE outgrown it. A mathematical
| model doesn't do any work. A piece of working equipment does. Your
| models don't deal wth real world issues, only what would be in a perfect
| universe. We designed and built $80,000 telemetry receivers without all
| your excessive math, and they worked so well that we couldn't keep up
| with the orders for a year or more. How many multi-million dollar
| contracts do you get from your anal retentive math?
Based on the math you've show you can do, I don't want to be anywhere near
those hazards.

It depends on the burst circuit. they are not all created equally.
Early tube circuits wouldn't lock properly. modern, solid state will
lock over a wider range. you haven't specified anything other than you
like to do math, which doesn't take into account the subtle variations
in the real world. Typical of those with a glass belly button.

getting the math right can lead you down false trails without the
proper experience.

i didn't say i did. It was a early '50s RCA design. My job was to
dismantle a dead transmitter, move it several hundred miles, and make it
work again. No support from RCA was available, so i had to take an
existing design with almost no documentation and make it meet FCC
specifications again. I did all the math with a TI pocket calculator.

Not a problem. You could never get the proper security clearance to
enter the sites where they are used. NASA, NOAA, the European Space
Agency and other government agencies had no problems with the design, so
whatever you think of it isn't worth a plugless nickel. They don't
launch anything at the cape without our products. Another product they
use are 'command destruct receivers', but I would think they are about
out of them, by now.

On Sun, 02 Mar 2008 22:11:10 -0500 Michael A. Terrell
|> Why would I have broadcast grade studio equipment at home?
|
|
| To prove your design. That is, unless you're a clueless hack.
I'm not making designs of broadcast equipment. I'm explaining bits of
the math that should be used in such a design. Spending the money on
such equipment to prove anything to you is not worth it. You are not
worth it.
And clearly it is not worth even posting to you, because you are so
closed minded about technology. So I guess I'll stop soon.
|> And did you have to do math? Vector math? Trig? I wonder what part|> you would have failed at if you had been called on to do it.
|
|
| i know, you're a "Just Spice It" type.
See, you really do make up things.
|> | Small potatoes. Have you designed an FQPSK encoding system, and the|> | decoding system? Hell, I've designed and built test fixtures that were|> | more complex. NTSC encoders were done with a handful of tubes and a|> | delay line for the sync. have you ever designed video amps with a 3 dB|> | point at 40 MHz, and less than .5 dB ripple over the entire pass band?|> |> And yet you don't know how many degrees of phase change take place between|> two sine waves only 2 Hz apart in frequency over the time a one video line?
|
|
| It depends on the burst circuit. they are not all created equally.
| Early tube circuits wouldn't lock properly. modern, solid state will
| lock over a wider range. you haven't specified anything other than you
| like to do math, which doesn't take into account the subtle variations
| in the real world. Typical of those with a glass belly button.
If it has the correct number of cycles over the long term (a second)
then it is in sync. If the number of cycles is different, it is not
in sync (and you'll have a funny pattern of changing colors).
|> Sure, experience helps. But getting math wrong can still destroy any|> design project.
|
|
| getting the math right can lead you down false trails without the
| proper experience.
You need both.
|> |> No I have not matched a set of 16 6146 tubes. This relates to
understanding
|> |> the color subcarrier how?|> ||> ||> | Phil, you don't understand much of anything. If that distributed|> | amplifier isn't balanced, the chroma doesn't get to the modulator. The|> | burst was the highest frequency passed by the video amplifier, and|> | mismatched tubes cause a loss of response at the higher frequencies, and|> | some phase shift.|> |> So if those 16 tubes are not perfectly matched, no signal gets out at|> all? Maybe you need a whole different approach.|> |> Why are you using 6146 tubes to pass chroma? Oh, wait, you didn't design|> this.
|
|
| i didn't say i did. It was a early '50s RCA design. My job was to
| dismantle a dead transmitter, move it several hundred miles, and make it
| work again. No support from RCA was available, so i had to take an
| existing design with almost no documentation and make it meet FCC
| specifications again. I did all the math with a TI pocket calculator.
I bet all those extra digits on that calculators was scary to you.
| Not a problem. You could never get the proper security clearance to
| enter the sites where they are used. NASA, NOAA, the European Space
| Agency and other government agencies had no problems with the design, so
| whatever you think of it isn't worth a plugless nickel. They don't
| launch anything at the cape without our products. Another product they
| use are 'command destruct receivers', but I would think they are about
| out of them, by now.
The government buys lots of junk that can't do the job right. Why is your
junk any different?

On Mon, 03 Mar 2008 10:23:26 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> On Sun, 02 Mar 2008 22:11:10 -0500 Michael A. Terrell|> |> |> Why would I have broadcast grade studio equipment at home?|> ||> ||> | To prove your design. That is, unless you're a clueless hack.|> |> I'm not making designs of broadcast equipment. I'm explaining bits of|> the math that should be used in such a design. Spending the money on|> such equipment to prove anything to you is not worth it.
|
|
| Bullshit. You don't know what you're talking about, as usual. Try
| spouting your igonrance on news:sci.electronics.design and they'll ter
| you a new asshole. Thn you'll have three.
There's no ignorance in what I say. If there was, anyone who wanted to
point it out would have been specific and said exactly what was wrong.
No one did. A couple of jerks (you being one of them) came along to take
pot shots because they have some serious attitude problems. That's all
it is.

On Mon, 03 Mar 2008 14:48:09 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> On Mon, 03 Mar 2008 10:23:26 -0500 Michael A. Terrell|> |>|> |> On Sun, 02 Mar 2008 22:11:10 -0500 Michael A. Terrell|> |>|> |> |> Why would I have broadcast grade studio equipment at home?|> |> ||> |> ||> |> | To prove your design. That is, unless you're a clueless hack.|> |>|> |> I'm not making designs of broadcast equipment. I'm explaining bits of|> |> the math that should be used in such a design. Spending the money on|> |> such equipment to prove anything to you is not worth it.|> ||> ||> | Bullshit. You don't know what you're talking about, as usual. Try|> | spouting your igonrance on news:sci.electronics.design and they'll ter|> | you a new asshole. Thn you'll have three.|> |> There's no ignorance in what I say. If there was, anyone who wanted to|> point it out would have been specific and said exactly what was wrong.|> No one did. A couple of jerks (you being one of them) came along to take|> pot shots because they have some serious attitude problems. That's all|> it is.
|
|
| Ok, if it floats your boat, Phil. Believe that you're the only one in
| the world who is right. Haven't you noticed that no one is backing you
| up? A sane person takes that into consideration.
You actually think anyone else is following this thread?

On Mon, 03 Mar 2008 23:48:04 -0500 Michael A. Terrell
| snipped-for-privacy@ipal.net wrote:
|> |> On Mon, 03 Mar 2008 14:48:09 -0500 Michael A. Terrell|> |>|> |> On Mon, 03 Mar 2008 10:23:26 -0500 Michael A. Terrell|> |> |>|> |> |> On Sun, 02 Mar 2008 22:11:10 -0500 Michael A. Terrell|> |> |>|> |> |> |> Why would I have broadcast grade studio equipment at home?|> |> |> ||> |> |> ||> |> |> | To prove your design. That is, unless you're a clueless hack.|> |> |>|> |> |> I'm not making designs of broadcast equipment. I'm explaining bits of|> |> |> the math that should be used in such a design. Spending the money on|> |> |> such equipment to prove anything to you is not worth it.|> |> ||> |> ||> |> | Bullshit. You don't know what you're talking about, as usual. Try|> |> | spouting your igonrance on news:sci.electronics.design and they'll ter|> |> | you a new asshole. Thn you'll have three.|> |>|> |> There's no ignorance in what I say. If there was, anyone who wanted to|> |> point it out would have been specific and said exactly what was wrong.|> |> No one did. A couple of jerks (you being one of them) came along to take|> |> pot shots because they have some serious attitude problems. That's all|> |> it is.|> ||> ||> | Ok, if it floats your boat, Phil. Believe that you're the only one in|> | the world who is right. Haven't you noticed that no one is backing you|> | up? A sane person takes that into consideration.|> |> You actually think anyone else is following this thread?
|
|
| Obviously you are. Tell me something, Phil. Do you ever watch the
| news and see either weather satellite photos, or NASA's live video feeds
| from space?
Of course I am ... I started the thread.
Why don't you ask that question in a thread you start. I don't see how
that even connects to this thread.

Of course you don't, but that great video is received with the
equipment you dammed in another message. The designs you called
garbage. The Microdyne MFR system we built and delivered to Wallops
Island Virginia to NOAA replaced the Harris equipment they bought on
competitive bid, that had a horrible failure rate. The old Harris
system was parted out and sent to their other earth stations. We were
to provide onsite engineering and a team of techs to fine tune the
system to satisfy the contract.
The pre-wired and tested equipment racks arrived a couple days
early. The engineers arrived a day early, and uncrated the equipment
that night. They bolted the racks together, and plugged the harnesses
back in, they turned it on. They connected it to the existing system's
antenna test port, which was -20 db from what that system used. They
packed up their tools and went back to their hotel rooms.
When they walked in the next morning, and were met by the facilities
manager who told them they were finished, and to go home. Then he said,
By the way. Your system locks onto the LEO birds a full five minutes
over the horizon.
This was the ONLY system capable of that trick, due to our
proprietary Doppler compensation circuits. All of this was designed and
built without your anal retentive math. Nothing ever went more than
four decimal places, because the best components on the market were 1%
capacitors, and .1% resistors. I'm sure anything you designed with your
anal retentive ideas would have been absolutely useless, because you
would spec parts that had to be all hand selected.
Another thing: A lot of Radio and TV stations still use our old 1100
series C-band equipment, and a lot of CATV headends still have Microdyne
equipment in daily use, with the same clear and stable video.
If our designs are so bad, as you claim, why did Scientific Atlanta
copy one of our telemetry receiver designs, instead of design their
own? Before you try to say it wasn't copied, Scientific Atlanta lost
the court case and was forced to stop building their clone.
Once again, you are WRONG.

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